Introduction
Agriculture is the single largest livelihood sources in India with nearly two
thirds of people depend on it. Rainfed agriculture is as old as agriculture it self.
Growing of crops entirely under rainfed conditions is known as dryland agriculture.
Depending on the amount of rainfall received, dryland agriculture can be grouped
into three categories:
1.2 Definitions
a) Dry farming: is cultivation of crops in regions with annual rainfall less than 750
mm. Crop failure is most common due to prolonged dry spells during the crop period.
These are arid regions with a growing season (period of adequate soil moisture) less
than 75 days. Moisture conservation practices are necessary for crop production.
b) Dryland farming: is cultivation of crops in regions with annual rainfall more than
750 mm. In spite of prolonged dry spells crop failure is relatively less frequent. These
are semi arid tracts with a growing period between 75 and 120 days. Moisture
conservation practices are necessary for crop production. However, adequate
drainage is required especially for vertisols or black soils.
C) Rainfed farming: is crop production in regions with annual rainfall more than
1150 mm. Crops are not subjected to soil moisture stress during the crop period.
Emphasis is often on disposal of excess water. These are humid regions with growing
period more than 120 days.
United Nations Economic and Social Commission for Asia and the Pacific
distinguished dryland agriculture mainly into two categories: dryland and rainfed
farming. The distinguishing features of these two types of farming are given below.